Two types of ethical theories:

Utilitarian (e.g. the greatest good for the greatest number; the end justifies the means): rules and acts selected on the basis of consequences, i.e. outcomes.
As expressed by David Hume, Jeremy Bentham, and John Stuart Mill.

Deontological (e.g. the Golden Rule): actions selected not just for their consequences but  for other reasons such as being truthful, keeping promises, seeking justice.
As expressed by Immanuel Kant, John Rawls, and Robert Nozick.
 

Common principles of bioethics:

Respect for Autonomy

Nonmaleficence

Beneficence

Justice (as Fairness)
 

See:
Beauchamp, Tom L., and Childress, James F. 1979-later, for subsequent editions. Principles of Biomedical Ethics.